688401616 has 80 divisors (see below), whose sum is σ = 1632038400. Its totient is φ = 274713984.

The previous prime is 688401611. The next prime is 688401629. The reversal of 688401616 is 616104886.

It is a super-2 number, since 2×688401616² = 947793569822822912, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688401611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122811 + ... + 128293.

It is an arithmetic number, because the mean of its divisors is an integer number (20400480).

Almost surely, 2^688401616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688401616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (816019200).

688401616 is an abundant number, since it is smaller than the sum of its proper divisors (943636784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688401616 is a wasteful number, since it uses less digits than its factorization.

688401616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5576 (or 5570 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 688401616 is about 26237.4087135144. The cubic root of 688401616 is about 882.9727357236.

The spelling of 688401616 in words is "six hundred eighty-eight million, four hundred one thousand, six hundred sixteen".